Means for tuning radio receivers



Oct. 30, 1951 R w. NN 2,572,965

MEANS FOR TUNING RADIO RECEIVERS Filed Sept. 30, 1948 2 SHEETS-SHEET l inventor 82 Rzb/iara (Yezzzam BI I 6 .22. MW attorney Oct. 30, 1951 R; w. AKEMANN 2,572,965

MEANS FOR TUNING RADIO RECEIVERS Filed Sept. 30, 1948 2 SHEETSSHEET 2 Zmoentor Patented Oct. 30, 1951 MEANS on TUNING RADIO RECEIVERS Richard W- Akemann, orno Ind es i n r t Genera Mo ors Corp ion D t it, Mi

o po a ion o D aw Application September 30, 1948, Serial No. 52,067

This invention relates to tuning means for radio apparatus and more particularly to com: bined automatic and manual tuning means, the automatic means :being specifically designed to scan the frequency band being received through some driven source. It has been somewhat con,- ventional to provide radio receiving sets which are automati ally tuned by b n driven hr a motor, the motor being controlled in various manners to index the receiver to certain prede: te mine s a ions. Obviously here must be a dri i o n c ion bet een t motor and the uning mean n t is has in man in tances taken t e te m of sear n h t e same tim it f, o cou se us iul to r de s me manu lly con o means for s tt n the cei r to oere n s ed stations, wh ch an be operated over a d a ove any u o t c, pe ation rough he moto dr t ha b en ome hat d flicul to r vid a m nua dri inasmuch as he mo o drive comprises a considerable load to be driven by he m n a plu the d iho lties of tappin into the dri at o e redet rm ed po nt, nd. s l providing through either source of actuatign pra t ca and t a t ol tfun r More re cently there has come upon the market receiver tuning means which is actuated by the incomin signal itself. These are provided with some ou e f power fo ni r uh s the rece r o e band and t n nd xin for stopping the tuner when a signal is received, some of these have had manual means in addition for setting the set and some have not t is h j t of my in entio to prov de compound manual and motor driven connection for the tuning means of radio apparatus.

It is a further object of my invention t9 provide direct mechanical connections between a manually operated knob and motor driven equipment, alternately operable for tuning radio apparatus,

With these and other obj ects in view, which will become apparent as the specification proceeds, my invention will be best understood by reference to the following specification and claims and the illustrations in the accompanying drawings, in which:

Figure 1 is a top plan view of a tuner embodying my invention.

Figure 2 is an enlarged partial top plan view with parts broken away and shown in section of the gear train and drive embodying my invention.

' Figure 3 is a vertical sectional view taken on line 3-..-3 of Figure 2 in the direction of the arrows.

Figure 4 is a vertical sectional view. taken on line E of Fi ure 1 i t direction of the HQWS- Fi ure 5 is a ve tica s c a w taken on line 5-5 or Fi ure 1 i the i e ti n oi the QWS; and

Fi ure 6. a secti al v ew tak n n ne 66 of Fi ure 5 in the rect on f arr ws.-

Re er i n w mo e s ecific lly o the draw in s, it i o ou se we l known t at. i tun n radio pp ra u it is convent na to vary ei her the capacity or the ind ctance he onant. tun d c rc ts r th apparatus- T r is lust ed i th acc m nying d awi s a tuner utilizin v riable in u an e f r t ni bu it. will be obvious that my invention cguld be equally as wel a pl ed to an ot er form o t n n suc as cond nser t nin and tha h pres nt show in s fo llus ra ve urposes o Referring now more spe fica t the drawings, there show ther n a home v2 upon which are. supp rt d a plura y f induc an e coils 4, .6 and it wh ch a ada ted t b con: nected into. e res nan i u ts f a adio reeiver, and t e values are adapted to ch n ed by the insertion or w thdrawa of a ries of corn: inuted cores Ill, w ch may be i sert d into or withdrawn from the coils. These cores are formed of very highly comminutefil material and compressed under high pressure, and have staked into one end thereof a supporting wire or thin rod l2 terminating in a screw threaded end portion 14, which is carried by a transverse bar I5. The threaded ends engage threaded openings in the bar and may be adjusted with respect thereto for alignment purposes. The bar projects through slotted openings. [8 in opposite sides of the frame, and may slide back and forth longitudinally thereof to carry the cores. Pivotal links 26 are connected adjacent opposite ends of the bar for driving purposes and in turn are pivotally con= nected to upstanding arms 22, which are con: nected to and turn the transverse shaft 24, this shaft being rotatably supported on the frame in any suitable manner.

Mounted on one end of the shaft just inside the frame is a sector drivin gear 26, which, when rotated, turns this shaft, and through the link system moves the bar l6 back and forth to tune the coreecoil assemblies. Mounted in the wall of the frame is an elongated bearing member 28, which is adapted to rotatably support a stub shaft 30, which carries on its inner end a pinion :32 which engages the sector gear 26. to drive the, same. A circular groove in the shaft 3.0 ad= jacent the outer end of the bearing member 35 has snapped thereinto a spring member 34, which maintains this shaft against endwise motion. Secured to the outer face of the frame, and adjacent the bearing 28, is a supporting plate 36 which has two spaced upturned cars 38 and 48, in which are aligned openings to rotatably support a drive shaft 42. This shaft 42 is positioned at right angles to and below the stub shaft 38. A motor 44 for driving the tuner is supported by the frame, and its shaft 46 projects through the supporting plate and carries on its outer end a worm drive 48 secured to the shaft by a set screw or other suitable means.

Fixedly secured to the shaft 42, adjacent the right hand end, as viewed in Figures 1 and 2,

is a gear 58 adapted to engage the worm 48 and .be driven thereby. This provides a drive for the shaft 42. To the left of gear 58 there is secured Upon the inside face of the crown gear 98 there are mounted in spaced relation two circular rings 98 and I88, both of which, of course, have an opening through the center to accommodate the shaft 38 and form a planet carrier for inte gral planet gears I82 and I84, which are mounted on a short shaft between the two rings and are secured together to rotate as a unit. The planet gear I82 is adapted to mesh with the sun gear 88, and planet gear I84 is in mesh with sun gear 88 on collar I6. The provision of the various apparatus just described enables the tuning means to be driven either through the motor 44 automatically actuated and controlled, or through manual rotation of the knob 96, and the operation of such drive will now be described.

Let it be assumed first that it is desired to operate the tuner manually and in this case, of

by a set screw a collar 52 on said shaft 42 which is adapted to engage the friction material 68 carried by the opposing clutch face 58. Thus, the motor 44, when energized, will drive the shaft 42, but worm 62 will not be driven unless the clutch is in engagement.

Pivotally mounted on the plate 36 is a clutch operating arm 66, which has a portion having an opening therein through which the shaft projects and which provides opposite arms 68 and I8 which extend down around the clutch member 58 and bear against the same to force it into engagement with the opposing clutch face 64 when pressure is applied to the lower end thereof through engagement with a bar 12 operated by solenoid 14. When the solenoid is energized, the armature is drawn inwardly and the clutch op-' erating arm 86 is rotated clockwise about its pivot, as shown in Figure 5.

Rotatably mounted upon the stub shaft 38 is a collar I8, which has rigidly secured thereto and on i adapted to rotate therewith two spaced gears 18 and 80, the first mentioned gear I8 being mounted directly over the worm 62 and being in mesh therewith and driven thereby. Any rotation, of course, of the gear 18 rotates gear 88. Mounted upon the outer end of the stub shaft 38 and rigidly connected thereto by a set screw, is a large wheel 82 which is adapted to drive certain indicating apparatus (not shown) on the receiver tuner through a cord 84. This wheel is supported on a collar 86, the inner end of the collar having rigidly secured thereto a gear 88, which, of course, will rotate with the shaft 38 and drive the same, inasmuch as the collar is rigidly secured thereto. Rotatably mounted on the collar 86 is a crown gear 98, whose teeth are adapted to engage a spur gear 92 carried on a manually operable shaft 94, which projects through the front panel of the tuner and has a manually operable knurled knob 96. The friction between the shaft 94 and the bearings through which it passes is suificient to maintain it against movement when the gear v88 is driven by the motor and, therefore, gear 88 must rotate under these conditions. 1

course, the motor 44 will remain at rest. Therefore, the worm gear 48 will be stationary and through its engaging gear 58 will lock shaft 42 against rotation. The clutch 5864, however,- is not energized, and, therefore, worm wheel 62 is free to rotate. It, however, is in engagement with gear 18 and tends to act as a lock for thesame when the drive is from gear to worm, which is, .of course, the opposite of the normal functioning in which the drive is from worm to gear.

This looks gear I8 in position, which in turn locks sun gear 80 and maintains it stationary,- inasmuch as the two are mounted on the same collar. Rotation of the manual knob 96 will, therefore, cause the pinion 92 to rotate, turning the crown gear 98 about its axis. This carries 1 the planetary carriage around the axis of the shaft 38, and since planetary gear I84 engages now stationary gear 88, planetary gear I82 will be rotated about its axis through the drive 88-I84. Since gear I82 meshes with sun gear 88,- it-will drive the same, and since that gear is rigidly secured to the shaft 38, will cause the shaft to rotate and the drive between gears 32 and 26 will cause thetuner to be moved. In other words, sun gear 88 is now the reaction element around which the planetary system moves.

On the other hand, if it is assumed that it is desired to operate the set automatically through the motor drive, manual knob 96 will remain stationary and through its pinion 92 lock the crown gear 98so that the latter will not rotate; then the drive from motor 44 to the tuning means will be from the armature shaft 46 through worm 48 to gear 58, which will drive shaft 42. Under automatic operation, clutch solenoid I4 is energized and clutch 58--64 will be closed todriveworm 82 from shaft 42. Rotation of worm 62 will drive, in turn, gear I8, and with it gear 88, which I is secured to the same collar. Gear 88, which, as before mentioned, meshes with planetary gear I84, will drive the latter, and the associated planetary gear I 82 secured rigidly to gear I84 will now directly drive sun gear 88, secured to shaft 38. In this case the planetary carriage will not move and the drive will be a straight. gear.

.- either sourceiof power.

Iclaim:

1. In radio apparatus, movable means for tuning said apparatus over a predetermined band of frequencies, a driving motor, a worm connected to the motor to be driven directly thereby, a countershaft, a worm gear mounted on the countershaft meshing with said worm, a second worm mounted on the countershaft, a second Worm gear meshing with the second worm, a sun gear directly connected to the second worm gear, a second sun gear directly connected to the movable means for tuning said apparatus, a planetary gear system mounted to engage both sun gears, and manually driven frictionally loaded means connected to the planetary system to drive the same or lock it as desired.

2. In radio apparatus, movable means for tuning said apparatus over a predetermined band of frequencies, a driving motor, a worm connected to the motor to be driven directly thereby, a countershaft, a worm gear mounted on the countershaft meshing with said worm, a second worm mounted on the countershaft, clutch means interposed between the worm gear and the second worm, magnetic means for actuating said clutch, a second worm gear meshing with the second worm, a sun gear directly connected to the sec-- ond worm gear to rotate therewith, a second sun gear directly connected to the movable means for tuning said apparatus, a planetary gear sys-- tem mounted to engage the sun gears, and manually rotatable frictionally loaded means connected to the planetary system to drive the same or lock it against rotation.

3. In radio apparatus, movable means for tuning said radio apparatus over a predetermined band of frequencies, a driving motor, clutch means having a connection to the driving motor, electrical current responsive means for actuating said clutch means, irreversible gear means having a connection to the clutch means, manual drive means, gear means having appreciable resistance to turning connected to the manual drive means, and differential gear means interconnecting the irreversible gear means, the gear means having appreciable resistance to turning and the movable means for tuning said radio apparatus, so that either the driving motor or the manual drive means may independently move the movable means for tuning said radio apparatus with said gear means having appreciable resistance to turning and said irreversible gear means acting as respective reaction points in said differential gear train.

4. In radio apparatus, movable means for tuning said apparatus over a predetermined band of frequencies, a motor drive, a worm driven by said motor, clutch means interposed between the motor drive and the worm, magnetic means for actuating said clutch means, a worm gear meshing with said worm, a manually driven frictionally loaded shaft, reduction earing connect ed thereto, gearing connected directly to the movable means for tuning said apparatus, and planetary gearing carried by said reduction gearing and interconnecting the worm gear and gearing connected to the movable means for tuning said apparatus to provide for independent actuation of the last mentioned means by either the motor drive or the manually driven frictionally loaded shaft.

5. In radio apparatus, movable means for tuning said radio apparatus over a predetermined band of frequencies, motor drive means, irreversible worm-gear drive means connected to the motor drive means, manual drive gear means having a constant and appreciable frictional load, and differential gear means interconnecting said irreversible worm-gear drive means, the manual drive gear means, and the movable means for tuning said radio apparatus, so that either the manual drive gear means or the motor drive means may independently move the movable means for tuning said radio apparatus as a result of the inherent resistance offered by the other of said drive means.

RICHARD W. AKEMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,059,366 Kinzie Nov. 3, 1936 2,372,099 McGarvey Mar. 20, 1945 2,398,346 Anderson Apr. 16, 1946 

